Skip to main content
BIIB logo

BIIB

Biogen Inc.
$191.95 -17.08 (-8.17%) At close · Jul 14
Market Cap
$28.34B
Shares
147,637,117

Institutional ownership from SEC Form 13F filings. Investment managers with more than $100 million in U.S. equities must disclose their positions every quarter, within 45 days of quarter-end, so the holdings shown can lag the market by up to a quarter.

The Jun 30, 2026 filing window is still open — showing the latest known positions. Funds that have not filed yet carry their prior-quarter positions; a fund that filed without this stock counts as sold out.
Holders: 1,012
Total Value: $24,129,816,647
Total Shares: 131,487,073
Showing 1–100 of 1,054 holdings by value · page 1 of 11

Institutional Ownership Trend

26 quarters

Holder Concentration

Across 1,008 13F filers
Top Holder
12.2%
Jun 2023 → Mar 2026 · range 12.0% – 12.8%
of institutional value
Top 5
45.8%
Jun 2023 → Mar 2026 · range 41.9% – 46.2%
of institutional value
Top 10
56.0%
Jun 2023 → Mar 2026 · range 53.8% – 59.3%
of institutional value
HHI
496
Jun 2023 → Mar 2026 · range 454 – 553
Broadly held
Showing 100 of 1,054
Export CSV
Holder Value (USD) % of 13F Shares Open
Key facts CIK 875045 CUSIP 09062X103 13F (30d) 121 filings 87 filers Visit website Investor relations